Find the 5th term, 8th term, and nth term of the G.P. 3, 27, 81, 243, …

Answer 1

It's not a geometric progression. It becomes one if we insert a 9 between the 3 and 27. In that case, the GP is defined as 3ⁿ, n = 1, 2, 3. ...

In that case, the fifth term would be 3⁵ = 243 and the eighth term would 3⁸ = 6561

Alternatively, we could replace 3 with 9, in which case the GP would be defined as 3ⁿ⁺¹, n = 1, 2, 3. ..., in which case the fifth term would be 3⁵⁺¹ = 3⁶ =729 and the eight term would be 3⁸⁺¹ = 3⁹ = 19683